Numerical Approaches for Submarine Hydrodynamic Design and Performance Analysis Stefano GAGGERO a , Benedetto PIAGGIO a , Giuliano VERNENGO a,1 , Diego VILLA a , Michele VIVIANI a , and Paola GUALENI a a Department of Electrical, Electronic and Telecommunications Engineering and Naval Architecture(DITEN), University of Genoa, Via Montallegro 1, 16145, GE, Italy Abstract. Submarines bring many interesting hydrodynamic challenges that need to be properly addressed to provide precise and reliable information about their performance. Hydrodynamic performance must be evaluated at least in two main operating conditions, namely when it is deeply submerged and at snorkel depth. There are relevant differences in terms of hydrodynamic since the forward speed in the latter condition is typically much lower and of interaction with the free surface. Moreover, submarines used to sail at snorkel depth if they need to accomplish spe- cific tasks, such as communication, that involves the use of surface piercing masts. The proposed study analyses the opportunity provided by different Computational Fluid Dynamic (CFD) approaches to correctly address submarine performance. The resistance in both conditions, masts free surface hydrodynamics and maneuvering behaviors are addressed. Ad-hoc approaches based on in-house developed numeri- cal procedures and open-source software are presented. Different CFD techniques have been used, including Reynolds Averaged Navire Stokes (RANS), Detached Eddy Simulation (DES) and Smoothed Particle Hydrodynamics (SPH), according to the particular physics that need to be studied. Keywords. Submarine, Computational Fluid Dynamics (CFD), Resistance, Maneuvering, Free surface flow 1. Introduction: CFD Methods for Submarine Hydrodynamics Submarines are assets of outstanding importance to implement strategies aimed at con- trol and protection of maritime domain. The fulfillment of their tasks and the success- ful completion of their operational profiles imply attentive investigations during the de- sign phase. Speed and range, for example, are among the most significant performance that need to be assessed, in relation to the submarine size and energy supply systems. The identification of the appropriate submarine configuration, able to comply with op- erational requirements, from one side is the result of systemic view that can guarantee that the high level performance are accomplished. On the other side, specific studies and analysis are necessary focusing for example on innovative energy system and storage solutions, innovative materials, structural details, hydrodynamic assessments. The per- 1 Corresponding Author: giuliano.vernengo@unige.it. Technology and Science for the Ships of the Future E. Rizzuto and V. Ruggiero (Eds.) IOS Press, 2022 © 2022 The authors and IOS Press. All rights reserved. doi:10.3233/PMST220035 279